title: Selection for malathion-resistance in Drosophila melanogaster.
abstract: Results from a long-term selection experiment for malathion-resistance in Drosophila melanogaster are described. A polled population of 40 locally-caught, iso-female lines was exposed to increasing concentrations of malathion in the food at both a high selection intensity (MH) and a lower intensity (ML). The response was consistent with a polygenic system. Both adult and larval resistance increased in parallel. Changes in the dose-response curve of adults could be approximately described by a dose-modification factor. Larval resistance was more complex; both selected populations showed a maternal effect which could not be explained by sex-linked genes. Larval resistance in the selected populations behaved as a co-dominant trait with respect to the susceptible controls. Adult resistance was dominant in the ML and co-dominant in the MH population, suggesting that different genes conferring resistance were selected. The selection procedure also produced a developmental delay in both populations, dependent on malathion concentration, but present even in its absence.
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D004331:Drosophila melanogaster / Q000235:genetics*; D005111:Extrachromosomal Inheritance; D005260:Female; D005799:Genes, Dominant; D007305:Insecticide Resistance; D008294:Malathion / Q000494:pharmacology*; D008297:Male
chemical_list: D008294:Malathion